krovlab

Give a building footprint in metres and a pitch in degrees. Get back a hipped roof, or a named failure. Units: metres and degrees. Source on GitHub.

Start from an example in the dropdown, or draw on the building plan. Click Update roof to rebuild the takeoff, the roof plan, and the 3D. Pitch is degrees (or a trade spelling such as 4:12 or 100%).

Load a catalog example (hip, gable, shed, mixed pitches, knee, gambrel, L-shape, courtyard, overhang, two cells, a dormer, a named failure).
Select a wall or corner on the plan, drag vertices, add a detached cell, add a cell on a selected wall, split a wall with a vertex, or delete a cell.
Set each wall to hip, gable, knee (with height), or gambrel (shallow pitch and break).
Give a cell an eaves overhang, an eave height, or a courtyard hole.
Apply one pitch to all sloping walls, or type coordinates in the table.
Edit a dormer that is already on the example (move it on the plan; hip or gable and pitch per dormer wall).
When Need help? is on the page: ask about this roof, or have the box fill those same wall and cell knobs. It does not add cells or dormers. Click Update roof after it writes the form.
Upload a DXF with one closed straight polyline in model space (and courtyard holes inside it). Choose millimetres, centimetres, or metres — millimetres is the default. Then click Update roof to rebuild the drawings.
When a three-dimensional roof is on the page, download it as roof.obj and roof.glb — one triangle mesh of the roof faces, in metres.

The Python library, Failure kinds, and what this roof family cannot represent are in the README on GitHub.

Building (edit)

Takeoff

terrain: True
ridge height: 3.000 m
total sloped area: 84.853 m²
eave: 32.000 m
hip: 20.785 m
ridge: 4.000 m
faces:
  edge 0: pitch 45°
  edge 1: pitch 45°
  edge 2: pitch 45°
  edge 3: pitch 45°

krovlab

Building (edit)

Takeoff

Roof plan

3D solid